This invention relates to a refrigerant system that is utilized in both heating and cooling modes, and wherein an economizer cycle is provided in both modes with a pair of alternate economizer heat exchangers.
Conventional refrigerant systems provide cooled air in an air conditioning mode and a heated air in a heat pump mode. Essentially, the refrigerant flow through the system is reversed to provide the two distinct modes.
One modern development in refrigerant cycles is the inclusion of an economizer cycle. An economizer cycle taps a portion of a refrigerant flow downstream of the outdoor heat exchanger in cooling mode or downstream of the indoor heat exchanger in heating mode. The tapped refrigerant is used to subcool the main refrigerant flow. The tapped refrigerant passes through an expansion device, where its temperature is reduced during the expansion process, and then through an economizer heat exchanger. In the heat exchanger, the tapped refrigerant exchanges heat with the main refrigerant flow. The tapped refrigerant is then returned to an economizer port of a compressor after having cooled the main refrigerant flow.
While economizer cycles are known in dedicated air conditioning cooling systems, and have been proposed for operation in heating mode of heat pump systems, there have been no effective solutions for combined air conditioning and heat pump systems that incorporate an economizer cycle, that can be used in the system during either cooling or heating mode of operation.